


Parallels and Differences

by antigrav_vector



Series: CapIM bingo fills - 2016 [6]
Category: Captain America (Comics), Captain America (Movies), Iron Man (Comic), Iron Man (Movies), Marvel (Movies), Marvel Cinematic Universe, The Avengers (Marvel Movies), The Avengers - Ambiguous Fandom
Genre: Cap_Ironman Bingo, Comic Book Science, Extremis, Feels, M/M, Pre-Established Relationship, Science, Tony Feels
Language: English
Status: Completed
Published: 2016-03-04
Updated: 2016-03-04
Packaged: 2018-05-24 17:30:53
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 799
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6161112
Author URL: https://archiveofourown.org/users/antigrav_vector/pseuds/antigrav_vector
Summary: <blockquote class="userstuff">
              <p>Tony and Tony discuss Steve and Science. And the differences in their pasts.</p>
            </blockquote>





	Parallels and Differences

**Author's Note:**

> For the Cap-Ironman Bingo prompt "jealousy." This falls in the same miniseries as [Statistical Mechanics and Mathematical Immersions](http://archiveofourown.org/works/5983804) and [The Pursuit of Happiness](http://archiveofourown.org/works/6043084), and is a direct sequel to [How My Lover Met Himself](http://archiveofourown.org/works/6155368).
> 
> Unbeta'ed.

Tony watched Steve disappear before he answered his multiverse double. "Yes?" he raised an eyebrow at the other him. "We're in a relationship. Is there a problem?" he asked coolly.

"No, no," came the reply. "Just... surprised."

"You're not together with your Steve, are you?" Tony guessed shrewdly.

"Not as such." His double shrugged. "I doubt my Steve would go for it."

Tony made a face. "Right. Okay. Not touching that one with a stick. You two have to work that out for yourselves. Look, we need a nickname for you, or this is going to get confusing."

"You mean it isn't already?" his visitor shot back. "My Steve calls me Shellhead."

Tony grinned. "That works."

"You got a nickname?" Shellhead asked him pointedly.

"Not one that I like." Tony replied. "Merchant of Death sounds badass, but it leaves something to be desired where reputation is concerned."

Shellhead winced. "That's fair. To work, then?"

"To work," Tony agreed. "Let's do this. What'cha got for me?"

Shellhead turned out to have the blueprints they needed memorised. The problem was working out what frequency to use. As it turned out, the frequency needed was based on the relative differences between the two universes in question, rather than any absolute measure. So first they had to figure out what their home universe's frequency was before they could send Shellhead home.

There was a lot of math involved, and Tony threw himself into it, with Shellhead right there at his side. It was... different, working with himself. There were a few people who could keep up with him, geniuses of their own field, but it was something else to work with someone who had the same talents but simultaneously completely different perspectives on what would work and what wouldn't. Based on his comments, physics seemed to work slightly differently in his home universe.

Once they had the equations beaten into shape, Tony put JARVIS on running the simulations and leaned back in his chair.

"So tell me something," he opened, watching Shellhead carefully.

"Depends what you want to know," his double replied carefully. "There are some things I can't tell you, and others I shouldn't."

"Right, right, proprietary shit, I get it." Tony waved that comment away. "I'm under similar restrictions."

Shellhead snorted. "Not quite. The kinds of things that have happened to us, all but tore the superhero community apart."

"What?" That was about as far from what Tony had expected as it was possible to be. He narrowed his eyes at Shellhead. "Meaning?"

"Meaning the same events could potentially happen here, and I don't want them to go as wrong as they did in our universe."

Tony rolled his eyes. "That's bullshit. If you tell me we have a better chance of preventing it from happening."

"That's what you think." Shellhead looked him over from head to toe. "You know, you're more idealistic than I expected."

"You say that like it's a bad thing." Tony returned the look, taking in the tired and defeated body language. "You're a lot more cynical than I expected."

"Hah!" Shellhead scoffed. "I'd have thought all those government contracts would have made you just as cynical. Or haven't they tried to put a leash on you yet?"

Tony grinned, but it wasn't a happy expression; the smile was sharp edged and brittle. "Oh, is that what this is all about? Government control? They tried and failed already."

Shellhead shook his head sadly. "They'll be back."

"Probably." Tony shrugged. "Can't deal with that until it happens, though. Preparations are already in place; I learned from Obie and Hammer."

"Who?" Shellhead gave him a confused look, then waved the question away. "Nevermind. Suffice it to say that I'm glad you haven't had to deal with that clusterfuck. And possibly a little jealous. It absolutely wrecked all of us." He slumped back into his own seat. "When Steve got shot it was almost the end of us all."

Tony gave him a sharp look, but didn't say anything. That paralleled his own nightmares a little too closely, and he didn't want to think about losing Steve. Not now.

After a short silence, Shellhead went on, audibly upset, but ruthlessly tamping it down. "If anyone tries to blackmail you into keeping secrets," he said, "say yes, but _don't_. Talk to your Steve. Don't make the mistakes I did."

Tony nodded, and decided it was time for a distraction. "Alright. But first things first. We need to give JARVIS time to run the sims, and you promised you'd tell me about extremis. That suit of yours is making me a little jealous."

The two of them barely noticed it when Steve re-entered the workshop, engrossed in their comparison of tech specs, available materials, and consequences. Tony _wanted_ those abilities for himself.


End file.
